Display panel

ABSTRACT

The panel comprises a gas-filled envelope which contains a plurality of column cathode strips which are oriented parallel to each other, with insulating means dividing the surface of each such strip into a column of a plurality of separate operating areas including display cathode areas and priming or scanning cathode areas, the latter providing excited particles for use by the display areas. The column cathode strips, thus treated, form rows and columns of display cathodes and priming cathodes, and, in each column, there are gas communication paths between priming cathodes or areas and display cathodes or areas. In addition, there are gas communication paths along each row of priming cathodes so that each priming cathode, and each column of priming cathodes, can diffuse excited particles to adjacent priming cathodes. A separate display anode is provided in operative relation with each row of display cathodes, and a separate priming anode is provided in operative relation with each row of scan cathodes, and each crossing of an anode and cathode area forms a display cell or a priming cell. 
     In operation of the panel, the columns of priming cells are energized successively, and simultaneously, information signals are applied to selected display anodes, and this causes cathode glow to transfer through the appropriate gas communication paths to the display cathodes associated with the selected display anodes, from the associated priming cathodes. The selected display cathodes thus energized in the panel display a message.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of application Ser. No.551,359, filed Feb. 20, 1975, abandoned.

BACKGROUND OF THE INVENTION

The principles of the invention relate to display panels of the typeknown as SELF-SCAN panels which are manufactured and sold by BurroughsCorporation. These panels are dot matrix devices which displaycharacters by energizing and generating light in selected cells in amatrix of cells, usually a 5 × 7 matrix, with the total number ofenergized cells displaying a character. SELF-SCAN panels includeseparate arrays of scanning cells and display cells which areelectrically connected to form a plurality of such 5 × 7 or othermatrices, with the scanning cells being adapted to assist in theenergization of selected display cells in accordance with input signalinformation. One form of SELF-SCAN panel is shown and described in U.S.Pat. No. 3,821,586. Panels of this type have achieved commercialsuccess; however, there is a constant need for simplification in thecomponent parts and structure of such devices for mass productionmanufacture. The present invention provides such simplification.

SUMMARY OF THE INVENTION

Briefly, a display panel embodying the invention includes a plurality ofparallel column cathode strips including means dividing the surfaces ofthe strips into a plurality of separate operating areas, with similarareas being disposed in alignment in rows. The columns of areas thusformed include scanning or priming cathodes areas and display cathodeareas, and separate anodes are provided for separately energizing eachrow of display cathodes and each row of priming cathodes. The panel isoperated by separately energizing each column of priming cathodes andselectively transferring cathode glow to the associated display cathodesin accordance with input signal information applied to selected displayanodes, the total number of display cathodes thus energized displaying acharacter or message.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded plan view of the parts of a display panelembodying the invention;

FIG. 2 is an enlarged view of a portion of the panel of FIG. 1;

FIG. 3 is a sectional view of a portion of the panel of FIG. 1assembled;

FIG. 4 is a sectional view, along the lines 4--4, in FIG. 1 showing thepanel assembled;

FIG. 5 is a sectional view, along the lines 5--5, in FIG. 1 showing thepanel assembled;

FIG. 6 is a schematic representation of the panel of FIG. 1 and acircuit in which it can be operated;

FIG. 7 is a plan view of a modification of a portion of the panel ofFIG. 1;

FIG. 8 is a perspective view, partly in section, of a panel modificationof the invention;

FIG. 9 is an exploded perspective view of the panel of FIG. 8;

FIG. 10 is an exploded plan view of the panel of FIG. 8;

FIG. 11 is a sectional view of the panel of FIG. 8;

FIG. 12 is an enlarged view of a portion of the panel of FIG. 8 shown toillustrate current flow therein;

FIG. 13 is a plan view of a modification of a portion of the invention;

FIG. 14 is a plan view of still another modification of a portion of theinvention; and

FIG. 15 is a plan view of another modification of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A display panel 10 embodying the invention, referring to FIGS. 1, 2, and3, includes a base plate 20 of insulating material such as glass,ceramic, or the like, and having a top surface 30 on which are provideda plurality of rectangular strips 40 of conductive material arrayedparallel to each other. The conductive strips or electrodes 40 areformed prferably by a screen printing process using any suitablematerial such as a mixture of nickel and glass frit in a suitablebinder.

An auxiliary conductive strip 41, used as a reset cathode in a scanningoperation to be described, is disposed adjacent to the first strip 40 atthe left-hand end of panel 10. This is arbitrarily considered to be theend at which the scanning cycle will begin. In addition, at least onekeep-alive cell is provided near the reset cathode and comprising twoelectrodes, a cathode 43 and an anode 45, both of which are preferablyformed on the base plate.

The conductive strips 40 are subdivided into rows of rectangular areas42 by means of thin parallel longitudinal lines 60 of insulatingmaterial formed on the top surface of the plate and on the strips 40.The lines 60 extend along the length of the base plate. In addition,each of the rectangular areas 42 of the strips 40 is subdivided by meansof insulating strips 62 formed on each rectangular area to subdivideeach such portion into a first, relatively large-area portion 44, to beoperated as a display cathode, and a second generally rectangular butsmaller portion 46, to be operated as a scanning or priming cathode. Thedisplay cathode portion 44 is connected to the scanning cathode portion46 by a narrow portion 48 which lies between the insulating portions 62.If a 5 × 7 dot matrix is to be used to form characters in panel 10, thenfive subdivisions 42 are provided in each strip 40.

The inulating strips 60 and 62 may be formed by a screen printingprocess.

It is noted that each portion 42 of a strip 40, referring to FIG. 2,thus comprises an electrode pair including electrode 44 and electrode46, and the electrode pairs and their component electrodes are allarrayed in rows and columns.

The panel 10 includes an insulating plate 70 seated on the base plate 20and resting on the insulating lines 60 and portions 62 which have athickness or height of about 2 mils so that they can support theinsulating plate 70 above the conductive strips 40. With plate 70resting on insulating portions 62, gas communication paths are providedbetween each display cathode 44 and its associated scan cathode 46through a path 74 extending along the narrow, constricted space 48between strips 62, as shown in FIGS. 2 and 3.

The insulating plate 70 includes a plurality of horizontal slots 76 and78, each slot 76 overlaying a row of display cathodes 44, and each slot78 overlying a row of scan cathodes 46. The lands or ribs 79 betweeneach slot 76 and the adjacent slot 78 overlay insulating portions 62 orinsulating lines 60.

The panel 10 also includes a transparent face plate 80 of glass or thelike, hermetically sealed to the center plate and the base plate by aseal 95, and carrying on its inner surface 82 a plurality of transparentconductive anode electrodes 90 of tin oxide or the like, each anodeoverlaying a slot 76 in the center plate and a row of display cathodes.The face plate also carries on its inner surface a plurality of opaquescan anodes 94, each overlaying a slot 78 and a row of scan cathodes.

The panel 10 is filled with a suitable ionizable gas such as neon,xenon, or the like, singly or in combination, at a suitable pressure.The gas atmosphere also includes mercury vapor to minimize cathodesputtering.

In panel 10, various parameters are selected to insure that one columnof cathodes glows at a time even though they are connected in groups.These parameters include the spacing of the columns of cathodes fromeach other, which, in one panel, was about six mils; the spacing of theface plate from the base plate, which was about 25 mils, and thepressure of the gas filling, which in such one panel was about 400 Torr.

Those skilled in the art will be readily able to modify these parametersto achieve the desired operation of modifications of panel 10.

In one mode of operation of panel 10, the strips 40 are electricallyconnected in groups by means of leds 50A, 50B, 50C, with every fourthelectrode being in the same group so that there are three such groups ofelectrodes. The interconnections 50 can be formed on base plate 20 atthe same time as the strips are formed, or they may be provided in anyother suitable manner. It will be clear to those skilled in the art,from the following description of the invention and from informationalready known about SELF-SCAN panels, that other electrode groupings canbe used or even that each electrode can be separately connected to anexternal cicuit However, the electrode groupings provide economies incircuit operation.

A system for operating panel 10 is shown in FIG. 6. In the system, thekeep-alive electrodes 43 and 45 are connected to a source of potentialV, by means of which the keep-alive cell is maintained continuallyenergized and generating exicted particles. The reset cathode 41 isconnected to a reset driver 96, and the groups of cathodes 40 areconnected by their conductors 50 to separate cathode drivers 100 forconnecting each cathode group in an operating circuit. All of the scananodes 94 are connected together through a suitable resistive path, ifrequired, to a source of generally positive operating potential 110.Each of the display anodes 90 is connected through a separate, suitablyresistive path to a source 116 of information signals which themselvesare connected to a data sopurce 120 which may include a computer,encoders, decoders, character generator, and the like circuit modules.Suitably synchronizing control circuits 130 are provided forinterrelating the various circuit elements to operate as describedbelow.

With the keep-alive cell ON, and all of the scan anodes 94 energized, apulse or other signal is applied by source 50R to the reset cathode 40Rwhich turns on, exhibits cathode glow, and generates excited particles.

The excited particles thus generated are present near the first columnof scan cathodes 46, and, when the first cathode driver 50A is operatedto connect the first column of scan cathodes in circuit with the scananodes, these scan cathodes turn on, exhibit cathode glow, and generateexcited particles. Although other columns of scan cathodes in the samegroup are energized at the same time, they do not glow. This is becausethe first column of scan cathodes 46 turns on preferentially because itis close to the reset cathode 100R and to the excited particlesgenerated thereby. These particles do not diffuse to the other columnsof scan cathodes in the group. In addition, when the first column ofscan cathode turns on, it quickly assumes sustaining potential which islower than the required firing potential for the other columns of scancathodes in its group.

As each of the cathode drivers 100 is operated in turn, each of thecolumns of scan cathodes is energized and exhibits cathode glow, inturn, with each column providing excited particles for the next adjacentcolumn. The scan cathode glow is not visible to a viewer since the scananodes 94 are opaque.

As each of the columns of scan cathodes is energized and the scancathodes glow, information signals applied to selected display anodes 90cause cathode glow to transfer from the scan cathode beneath andadjacent to the selected display anodes through the constricted path 48to the adjacent display cathode, beneath the selected display anode. Thedisplay cathode now glows, and this glow is visible to a viewer throughthe transparent display anodes. This operation is repeated for eachcolumn of electrode pairs, and the total scanning operation is repeatedcyclically throughout the panel at such a rate that the display cathodeswhich are energized present an apparently stationary but changeablemessage. This mode of operation described above is generally similar tothat employed in SELF-SCAN panels of the type described in theabove-mentioned patent.

The panel 10 may also use modified cathode strips 40 (FIG. 7) in whichthe rectangular areas 42 are subdivided by rectangular insulating strips62' formed on each such subdivided portion 42 and positioned close tostrips 60 to form a relatively large-area display cathode portion 44'and a relatively small-area scan cathode portion 46'. The strips 62' arespaced from the left and right edges of the cathode strips 40 to providea narrow constricted path 48' on each side of the strip. In operation ofa panel with cathode strips of the type shown in FIG. 7, glow transfertakes place from a scan cathode 46' to a display cathode 44' through thetwo gas communication paths 48'.

A panel 200 embodying a modification of the invention and shown in FIGS.8-12 includes a base plate 210 of glass or other suitable insulatingmaterial having a top surface 220 on which is formed a plurality ofparallel conductive strips 230 disposed generally transverse to thelongitudinal axis of the base plate. The conductive strips 230 areoperated as cathode electrodes in the completed panel, and they may beformed by a screen printing process as above. If desired, the conductivestrips may also comprise individual metallic elements suitably securedto the base plate.

A slotted insulating plate 240 is seated on the cathodes 230 to dividethem into generally rectangular elemental areas 230D and 230S. The slots244 and 246 in the plate are alternately wide and narrow so that thecathodes 230 are divided into alternately large and small areas which,as can be seen, are arrayed in rows and columns. In operation of thepanel, the relatively small cathode areas 230S are operated as scanningpr priming cathodes, and the relatively large areas 230D are operated asdisplay cathodes.

The panel is completed by a glass face plate 250 which carries, on itinner surface 260, a plurality of alternate wide and narrow anode strips270D and 270S, respectively, insulated from each other and disposedparallel to the longitudinal axis of the face plate and the panel. Therelatively wide anode strips 270D may be made of material such as tinoxide, and each of these overlays a row of display cathodes 230D.Adjacent to each transparent anode is an opaque anode film or strip 270Sof any suitable material, each of which overlays a row of scanning orpriming cathodes 230S. Thus, when display cathodes are energized andexhibit cathode glow, the glow is visible through their anodes 270D, andwhen scanning cathodes are energized and exhibit cathode glow, the glowis not visible through their anodes 270S.

Although they are not shown, panel 200 would include a reset cathode anda suitable keep-alive arrangement as required and as described above

The operation of panel 200 is essentially the same as the operation ofthe other panels described above except that, as columns of scanningcells are energized by the application of operating potential to thecathode strips and the scan anodes, the information signals are appliedto the display anodes, it is believed that glow is transferred from ascan cathode to the selected adjacent display cathode along the left andright hand edges of the cathode strip through the space betweeninsulating plate 240 and the top surface of base plate 210 asillustrated by the dash lines in FIG. 12.

Although, in the panel described above, a scanning or priming cathode orcell is associated with each display cathode or display cell, it isclear that other arrangements could be used as taught in U.S. Pat. No.3,683,364. For example, as illustrated schematically in FIG. 13, eachtwo display area D may have a priming area P between them; or, asillustrated in FIG. 14, priming areas may be provided at the upper andlower ends of a column of display areas D; or, as illustrated in FIG.15, a column of cathode areas may include a relatively random insertionof priming areas, and a column may include two or three display areas inseries, a priming area, then two or three display areas, then a primingarea, etc. In each case, any of the means described above may be used todivide the cathode surfaces, as desired.

The panel of the invention utilizes principles of operation and somestructural features of SELF-SCAN display panels which are made and soldby Burroughs Corporation. Panels of this type are described and claimedin the following copending applications and U.S. patents which areincorporated herein by reference:

Ser. No. 487,955 filed July 12, 1974

Ser. No. 551,539 filed Feb. 20, 1975

Ser. No. 624,531 filed Oct. 22, 1975

Ser. No. 624,532 filed Oct. 22, 1975

U.s. pat. No. 3,619,698

U.s. pat. No. 3,683,364

U.s. pat. No. 3,699,376

U.s. pat. No. 3,766,420

U.s. pat. No. 3,767,968

U.s. pat. No. 3,863,088

What is claimed is:
 1. A display panel comprisinga gas-filled envelopeincluding a base plate and a face plate having a viewing window, aplurality of columns of coplanar operating cathode areas which areelectrically connected in each such column, all of said cathodeoperating areas having upper surfaces facing said viewing window, saidcolumns of cathode areas including display cathode areas and primingcathode areas, said priming cathode areas providing excited particlesfor said display cathode areas through gas communication paths extendingalong said columns of cathode areas, said display areas and said primingareas also being disposed in rows, barrier means between said base plateand face plate and having portions which delineate said rows of displayareas and said rows of priming areas, .[.and.]. .Iadd.said gascommunication paths extending beneath said barrier means from primingcathode areas to display cathode areas, and .Iaddend. a priming anodeoverlying each row of priming cathode areas and a display anodeoverlying each row of display cathode areas, said barrier means alsoeffectively separating adjacent anodes from each other.
 2. The paneldefined in claim 1 wherein said priming cathode areas are hidden fromview by said priming anodes. .[.3. The panel defined in claim 1 whereinsaid barrier means comprises an assembly of a plurality of thin parallelinsulating plates positioned between said base plate and said faceplate, with said rows of cathode areas being disposed between adjacentplates..].
 4. The panel defined in claim 1 wherein said barrier meanscomprises a slotted .[.plane.]. .Iadd.plate .Iaddend.having a pluralityof parallel slots formed therein and extending along the long axis ofsaid plate, said slotted plate being seated on said cathodes with theslots therein extending transversely of said cathodes and crossing allof said cathodes, there being a separate slot overlying each row of saiddiscrete areas of said cathodes.
 5. A display panel as in claim 1wherein said display cathode areas and said display anodes definedisplay cells, and said priming cathode areas and said priming anodesdefine priming cells and includingmeans coupled to said display cathodeareas and said display anodes for applying each of a succession ofgroups of information signals to said display anodes and said columns ofdisplay cathode areas, and means coupled to said priming cathode areasand said priming anodes for producing a glow discharge in each column ofpriming cathode areas, and then in the remaining columns of primingcathode areas, one after the next, to scan said columns of primingcathode areas, one at a time, in synchronism with the application ofsaid successive groups of information signals, to produce glowdischarges in selective display cells adjacent the priming cathode areasbeing scanned, one after the next, to provide an overall glow dischargepattern directly in the display cells.
 6. The panel defined in claim 1wherein each column of cathodes includes a series of display cathodeareas and priming cathode .[.arreas.]. .Iadd.areas .Iaddend.whichalternate with each other.
 7. The panel defined in claim 6 and includingbarrier .[.mean.]. .Iadd.means .Iaddend.disposed between a displaycathode area and the adjacent priming cathode area, said barrier meansbeing shaped to provide a .Iadd.constricted .Iaddend.particlecommunication path between a priming cathode area and the adjacentdisplay cathode area.
 8. The panel defined in claim 1 whereineachpriming cathode and its associated priming anode comprise a glow primingcell, there thus being columns of glow priming cells, and each displaycathode and its display anode comprise a display cell, there thus beingcolumns of display cells, means for producing a priming glow dischargein all of the glow priming cells of a column of such glow priming cells,and then in all of the cells of the remaining glow priming cell columns,one column after the next, to scan the glow priming cells, and means forapplying each of a succession of groups of information signalsselectively to said columns of display cells, in synchronism with thescanning of the columns of glow priming cells to produce display glowdischarges in selected display cells.
 9. The panel defined in claim 1wherein each column of cathode areas includes a plurality of displayareas in series followed by a priming cathode area and this followed bya plurality of display cathode areas, followed by a priming cathodearea. The panel defined in claim 1 wherein each column of cathode areasincludes a plurality of display cathode areas and at least one primingcathode area.
 11. The panel defined in claim 1 wherein each column ofcathode areas includes a series of display cathode areas and primingcathode areas at the ends thereof.
 12. A display panel comprisingagas-filled envelope including a base plate and a face plate having aviewing window, a plurality of coplanar, parallel cathode electrodestrips supported in said envelope with their upper operating surfacesfacing said viewing window, barrier means extending across and dividingsaid operating surfaces of said cathode electrode strips into aplurality of discrete operating cathode areas including display cathodeareas and priming cathode areas, said display cathode areas beingaligned in rows and said priming cathode areas being aligned in rows, apriming anode electrode overlying each row of priming cathode areas anda display anode electrode overlying each row of display cathode areas,said barrier means being interposed between adjacent ones of saidanodes.
 13. The panel defined in claim 12 wherein said barrier meanscomprises an assembly of thin parallel insulating plates disposed onedge between said base plate and face plate and extending horizontallyto provide row channels in which said rows of display cathodes andpriming cathodes are disposed.
 14. The panel defined in claim 13 whereinsaid plates are supported on said cathode strips and are spaced from thebase plate by the thickness of the cathodes, the space thus providedserving as a particle communication path along a cathode strip.
 15. Thepanel defined in claim 12 whereineach crossing of a priming anode and apriming cathode area forms a priming cell, and each crossing of adisplay anode and a display cathode area forms a display cell, therebeing a series of columns of priming cells and display cells, means forapplying each of a succession of groups of information signals to eachof said columns of display cells in turn, and means for producing a glowdischarge in each column of priming cells, one after the next, to scansaid columns of priming cells, one at a time, in synchronism with theapplication of said successive groups of information signals, to produceglow discharges in selective display cells adjacent the priming cellsbeing scanned in each column, one after the next, to provide an overallglow discharge pattern directly in the display cells. . The paneldefined in claim 12 wherein said anodes are films formed on said faceplate and said priming anodes are opaque. .Iadd.
 17. A display panelcomprisinga gas-filled envelope including a base plate and a face platehaving a viewing window, a plurality of columns of coplanar operatingcathode areas which are electrically connected in each such column, allof said cathode operating areas having upper surfaces facing saidviewing window, said columns of cathode areas including display cathodeareas and priming cathode areas, said priming cathode areas providingexcited particles for said display cathode areas through gascommunication paths extending along said columns of cathode areas, saiddisplay areas and said priming areas also being disposed in rows,barrier means between said base plate and face plate and having portionswhich delineate said rows of display areas and said rows of primingareas, said barrier means comprising an insulating cell sheet disposedbetween said base plate and said face plate and having a plurality ofchannels defined by a plurality of thin parallel walls, each channelbeing aligned with a row of cathode areas and defining a row of primingcells or a row of display cells, and a priming anode overlying each rowof priming cathode areas and a display anode overlying each row ofdisplay cathode areas, said barrier means also effectively separatingadjacent anodes from each other. .Iaddend. .Iadd.
 18. The panel definedin claim 17 wherein said gas communication paths extend under saidbarrier means. .Iaddend..Iadd.
 19. A display panel comprising agas-filled envelope including a base plate and a face plate having aviewing window; a plurality of coplanar, parallel cathode electrodestrips supported in said envelope with their upper operating surfacesfacing said viewing window, barrier means extending across and dividingsaid operating surfaces of said cathode electrode strips into aplurality of discrete operating cathode areas including display cathodeareas and priming cathode areas, said display cathode areas beingaligned in rows and said priming cathode areas being aligned in rows,there being gas communication paths for excited particles along theedges of said cathode electrode strips beneath said barrier means whichrests on said cathode electrode strips, and a priming anode electrodeoverlying each row of priming cathode areas and a display anodeelectrode overlying each row of display cathode areas, said barriermeans being interposed between adjacent ones of said anodes. .Iaddend.